Methods and apparatuses for the removal of the remainder of tread stock on tire casings being prepared for recapping or retreading have been developed and are widely utilized in the industry. However, because of the great variety of sizes of tire casings, measuring in outside diameter all the way, for examples, from 18 inches to 48 inches or more, and because of the differing shapes and cross-sectional profiles of the casings both because of their constructions and because of the surface which must be prepared for the adhesion thereto of treads of different configurations, many problems have not been solved.
The Rubber Manufacturers Association has established criteria for identification of the buffed profile of casings which involve four measurements. There are the crown radius which may vary, say, from 5 inches to 36 inches; shoulder radius which may vary from, say, 1/2 inch to 2 inches; crown width which may vary from, say 3-1/2 inches to 18 inches; sidewall angle, usually in the range of 45.degree. to 60.degree., measured relative to the axis of the tire casing.
In discussion, the term "buffing" will be used to identify the removal of old rubber from the casing whether it is done by cutting wheels, texturizing wheels or finishing wheels.
In order to shape the buffed surfaces of casings having such widely varying measurements previous automatic apparatuses have been able to function only to perform some of the necessary buffing operations and the "eye" and manual actions of the operator have been utilized to prepare the "finished" portions of the side walls adjacent the edges of the retread material.
It is therefore the principal object of the instant invention to provide a tire buffing apparatus which is so designed as to enable the utilization of any profile template to control the buffed and finished surfaces of the casing, the template being selected according to the mentioned criteria for the particular casing being treated.
It is yet another object of the instant invention to provide a template guided buffing apparatus for shaping the surface, including the crown, the shoulder and the side wall of a tire according to a template selected by the four criteria mentioned and, in addition, as modified according to the type of tread to be adhered to the buffed casing, for example, snow tires, road tires, circumferentially grooved tires, lugged tires, etc.
Another important object of the instant invention is to provide a tire buffing apparatus having an articulated frame for mounting the tire to be buffed so designed and constructed as to enable the tire first to be treated by a rough cutting wheel in order to remove, say, 90%-95% or more of the old rubber and then to be treated by one or more texturizing and/or finishing wheels, the profile of the tire being buffed or cut away being controlled by a template selected according to its specific designation in accordance with the criteria mentioned above.
Yet another object of the instant invention is to provide a tire buffing apparatus having 2 or 3 buffing wheels, for examples, rough cutting, and/or texturizing and/or finishing wheels which successively may be utilized for shaping the surface of the tire casing to its desired profile and its surfaces to desired textures.
Yet another object of the instant invention is to provide a tire buffing apparatus in which the major portion of the buffing method is performed under the control of an appropriately selected template, which has means for over-riding the template profile by shifting the casing radially relative to the buffing wheels when desired, in order to permit the full treatment of the sidewall/tread junction areas of the casing which, for one reason or another, are not adequately finished under the control of the appropriate template.
A still further object of the instant invention is to provide a tire buffing apparatus on which casings of very different sizes and cross-sectional shapes may be mounted and their surfaces completely buffed without removal from the apparatus, with easy adjustment of the apparatus to accomodate the varying sized casings and templates for the control of their profiles, the apparatus also having adjustable and floating pivot means in order to enable the respective profile template to correctly position any particular casing being buffed.